Features • Up to four lines with independent configuration and registration • Active line indication, with name and number • Menu-driven user interface, with support for multiple languages • Digits dialed with number auto-completion • Shared line appearance** • Full-duplex speakerphone • Call hold • Music on hold** • Call waiting • Caller ID name and number • Outbound caller ID blocking • Call transfer - attended and blind • Call conferencing • Automatic redial • On-hook dialing • Call pickup - selective and group** • Call park and retrieval** • Call swap • Call back on busy • Call blocking - anonymous and selective • Call forwarding - unconditional, no answer, or busy • Hot line and warm line automatic calling • Call logs (60 entries each) - calls made, answered, and missed • Redial from call logs • Personal directory with auto-dial (100 entries) • Do not disturb (callers hear busy signal) • Uniform Resource Identifier (URI) (IP) dialing support (vanity numbers) • On-hook default audio configuration (speakerphone and headset) • Multiple ring tones with selectable ring tone per line • Called number with directory name matching • Call number using name - directory matching or via caller ID • Subsequent incoming calls with calling name and number • Date and time with intelligent daylight savings support • Call duration and start time stored in call logs • Call timer • Name and identity (text) displayed at startup • Distinctive ringing based on calling and called number • Speed dialing • Configurable dial/numbering plan support (per line) • Intercom** and group paging** • DNS SRV and multiple A records for proxy lookup and proxy redundancy • Syslog and debug server records (configurable per line) • Report generation and event logging • Statistics transmitted in BYE message • Secure call encrypted voice communication support - SIP over Transport Layer Security (TLS), and Secure Real-Time Transport Protocol (SRTP) • Built-in web server for administration and configuration with multiple security levels • Automated provisioning, multiple methods - up to 256 bit encryption (HTTP, HTTPS, Trivial File Transfer Protocol [TFTP]) • Asynchronous notification of upgrade availability via NOTIFY • Nonintrusive, in-service upgrades • Optionally require administrator password to reset unit to factory defaults